Among the applications for micromechanical devices are planar actuators comprising one or typically an array of actuators in a two-dimensional matrix in which individual elements of the array need to be individually and rapidly displaced.
In one application of such actuators to the deflection of radiation, an array of actuators includes mirrors activated by micromechanical electrostatic motivators to provide rapid displacement of the mirror positions in the array in order to alter the phase delay of incoming radiation wavefronts and thereby adjust the phase of the reflected light or the angle of reflection.
In modern high-speed systems such as scanners and pattern recognition systems, the demands for rapid adjustment of the phase of reflected light or beam angle continue to increase, placing severe demands upon control circuitry for an array of large dimensions to precisely and individually control each of hundreds or thousands of mirror elements in the array.
An additional problem encountered in controlling such actuators is the nonlinearity between displacement and applied control voltage due to the mathematical relationship between displacement and applied potential in what is essentially a parallel-plate capacitor geometry. To deal with the nonlinearity in order to provide accurate beam reflection, a heavy demand is placed upon processing electronics to accomplish any adjustment to the hundreds or thousands of individual actuators for controlling the position on an ongoing, rapid sequence basis.